fix(@schematics/angular): document jasmine options

Currently it can be hard to find how to configure Jasmine in the Karma config.
For example, a developer might want to reproduce a randomly failing test with a specific seed.

This commit adds some information that may be helpful to beginners.

Author: cexbrayat

packages/schematics/angular/application/files/karma.conf.js.template

@@ -13,6 +13,12 @@ module.exports = function (config) {
       require('@angular-devkit/build-angular/plugins/karma')
     ],
     client: {
+      jasmine: {
+        // you can add configuration options for Jasmine here
+        // the possible options are listed at https://jasmine.github.io/api/edge/Configuration.html
+        // for example, you can disable the random execution with `random: false`
+        // or set a specific seed with `seed: 4321`
+      },
       clearContext: false // leave Jasmine Spec Runner output visible in browser
     },
     jasmineHtmlReporter: {

packages/schematics/angular/library/files/karma.conf.js.template

@@ -13,6 +13,12 @@ module.exports = function (config) {
       require('@angular-devkit/build-angular/plugins/karma')
     ],
     client: {
+      jasmine: {
+        // you can add configuration options for Jasmine here
+        // the possible options are listed at https://jasmine.github.io/api/edge/Configuration.html
+        // for example, you can disable the random execution with `random: false`
+        // or set a specific seed with `seed: 4321`
+      },
       clearContext: false // leave Jasmine Spec Runner output visible in browser
     },
     jasmineHtmlReporter: {